Traditionally video display devices such as monitors and television receivers have been designed by physically constructing the device and testing the physical embodiment utilizing various test signals. In the design of the circuitry for the display device various parameters will affect the quality of the display image. These parameters include the bandwidth of the various amplifiers, the gamma of the cathode ray tube, the size of the electron spots on the cathode ray tube and the pattern of the phosphor on the display screen. Although various electrical measurements can be used to evaluate the design, in the end it is the viewer's perception of the displayed image which is the fundamental evaluation factor. One can easily appreciate that each of these parameters will independently affect the quality of the displayed image and several iterations of the prototyping may be necessary to visualize and test the effects of the design changes on the image presented by the display device.
In the prior art, the usual way of evaluating changes in various design parameters of the display device was to physically change the display device prototype. The physical prototyping and evaluation of the display device design was often expensive and time consuming.
With the advent of high speed, digital circuitry, the broadcast industry has now been presented with very sophisticated image processors capable of creating elaborate special effects, such as reducing or enlarging the size of the video image and altering the image on a picture element (pixel) by picture element basis. These image processors in conjunction with a computer digitize the video image so that each pixel can be represented by a separate digital word. The digitized image is mathematically processed in a high speed digital arithmetic unit so that the various pixels can be altered according to the preconceived effect. For example, these computer controlled image processors can be used to create a transition from one video image to another which can simulate the turning of a page in a magazine or a book. The processors can also be utilized to combine two separate images into one according to a given effect programmed by the operator.
A typical image proessor, such as the Gould/DeAnza model IP8500, provides memory for image storage and a digital arithmetic unit. The digital video processor actually is a series of arithmetic logic devices, each of which is capable of performing a mathematical function, such as addition, multiplication, logical AND, or logical OR. The arithmetic unit is capable of being controlled by a computer to electrically switch the connection of the inputs and outputs of the logic devices thereby configuring the arithmetic unit to mathematically process the image signal in almost an infinite combination of ways. The teleproduction special effects operator programs the image processor to set up a signal path so as to arithmetically alter the image according to the desired effect.